How one woman’s 21-day no-booze Facebook challenge put the brakes on a habit that was veering into the danger zone.

Two full hours lost, never to be retrieved from my memory bank again. It was last summer, and I was at a campground with friends. After a raucous evening, during which both the wine and the conversation were flowing abundantly, I woke up with a hangover and couldn’t recall how I had gotten back to my campsite, which was some distance away from the others.

When I discovered that a friend had escorted me to my tent, I asked her if I’d done or said anything stupid the night before. Apparently not.

But I did retell - over and over - a story my husband had shared with me on the phone earlier that day about his flight home from Cuba. The crew didn’t speak English and the pilot, circling the airport for hours during a rough storm, didn’t offer any words of consolation to the extremely agitated passengers beyond “Good luck!”

Apparently, I found this indescribably funny - so much so that I told this same story four (yes, four) times, taking particular relish in pronouncing the words “Good luck!” with a Spanish accent.

And I was loud. “I think the whole campground heard you,” my friend said with a laugh. She was smiling, but I was mortified. Try as I might, I couldn’t remember any of this. The amnesia was temporary, but it signalled that it was time for a permanent change.

I’d always thought a blackout was the same as passing out, but it isn’t. In the physiology of blackouts, you appear to be functioning normally, but as your blood alcohol level spikes, it shuts down the hippocampus, wiping out your long-term memory in the process.

It wasn’t exactly a lost weekend, but it was two hours I’ll never get back. It scared me enough to take action.

When I got home, I hammered out a Facebook post saying that I was starting a 21-day no-booze challenge and invited others to join a private online group where we could share articles, updates and encouragement as we cut out alcohol for three weeks.

Three weeks - how hard could it be? To my surprise, more than 40 people signed on. Like me, most of them were in midlife. Many said they drank more than they wanted to.

Until that blackout, I didn’t think I had a problem with alcohol - not a big one anyway. Sure, I seemed to drink more than most of my friends, and I woke up a couple of times a week with a low-grade headache because of imbibing the night before. But I never threw up, passed out or missed work because of it - wine was simply my way to unwind.

I began drinking almost daily about 10 years ago, when my kids were young and I needed a reward after a long day at the office and a second shift of toddler time at home. Come 9 p.m., the shiraz would be swirling merrily in my glass.

In her book Drink: The Intimate Relationship Between Women and Alcohol, Canadian journalist Ann Dowsett Johnston recounts her struggles with alcohol and her ensuing recovery jump-started by a stay at a treatment centre. She argues that booze has become “the mother’s helper of her generation,” replacing the tranquilizers that millions of housebound women were addicted to in the ‘60s.

“Alcohol is ubiquitous in our society,” she says. “It’s hugely linked to our notions of celebration, sophistication and well-being. It’s how we relax, reward, escape, exhale.”

Home life became less demanding when my kids got older, but by then I had started a business as a freelance writer and managed constant deadlines. When I shut down my laptop at the end of the day, wine was still my reward. Same went for my husband, a newspaper columnist who juggles three deadlines a week.

The satisfying sound of a cork popping and the glug-glug of wine pouring into a wide-brimmed goblet released the pressure valve for both of us. We could easily polish off a bottle of wine on most nights and often opened a second.

I never counted, but I knew I was well over the low-risk drinking guidelines recommended by Canadian health agencies (no more than two drinks a day on most days to a maximum of 10 drinks a week for women and no more than three drinks a day on most days to a maximum of 15 drinks a week for men).